1979 928 Master Warning Blinking - woudn't clear

The master warning is there for a reason … if it screams!!! Even more of a reason. On my 1979 just blinking like crazy and wouldn’t cancel out. I thought it was broken.

I was on my knees this morning working to remove that pesky diagnostic warning controller, I didn’t see a reason for it to be flashing therefore it must have failed.

While I was on my knees preparing to remove the diagnostic module, what did I see but brake fluid leaking from the clutch master cylinder. I then check the brake fluid reservoir and yes, it was more than ½ low. Once filled, the master warning was silent.

So, a 46 year old diagnostic system is working and doing a great job!! That is if trusted. Yet another lesson learned … check EVERYTHING before doubting that warning system.

Next, the dreaded clutch master cylinder replace. Ugh.

I was thinking the very same thing.  The last time mine did that (in 1997) it was the blue line that leaked brake fluid everywhere.